1. Field of the Invention
The present invention relates to a matrix-type display device, which is capable of repairing defective connection of a scanning line or a signal line required for driving the display device.
2. Description of the Prior Art
In order to repair a disconnected data signal wiring or a scanning signal wiring disposed in a display panel, conventional matrix-type display devices are internally fitted with spare wirings. An example of a schematic front view of a conventional matrix-type display panel is shown in FIG. 7. FIG. 7 exemplifies a conventional active matrix type liquid crystal display panel, which accommodates a liquid crystal layer on a substrate 10 consisting of a plurality of thin-film transistors (TFT) and then a substrate 20 having a color filter (CF) is laminated on the liquid crystal layer so as to complete assembly of an active matrix type display device. A number of tape carrier packages (TCP) 30 each consisting of an IC package using a tape film are tightly secured to the edge portion of the TFT substrate 10. Data signals are output from the TCP packages 30, which are horizontally aligned in FIG. 7, whereas scanning signals are output from the vertically aligned TCP packages 30 in FIG. 7.
In the event that either a data signal wiring or a scanning signal wiring has been disconnected, the disconnected signal wiring 40 is connected to a spare wiring 50 at an intersection 45 between them by way of fusing both wirings by applying, for example, a laser beam. In consequence, this results in the restored normal connection of one of identical signal wirings 40 thus far directly incurred disconnection via linkage through a discrete route that exists among a plurality of TCP packages 30.
In the case of a conventional display device, in order to provide a spare wiring with an antistatic effect, as previously proposed in the Japanese Laid-Open Patent Application No. H11-271722, by providing a protecting circuit, this preceding art related to the above-cited patent publication aimed at suppressing externally intruding ESD (external static discharge). In addition, as proposed via another Japanese Laid-Open Patent Application No. 2002-174820, in addition to the provision of a circuit analogous to the above-cited protection circuit, the latter art related to the above-cited patent publication aimed at coping with static charge by way of providing a dummy spare wiring.
However, it is essential for the above-cited conventional arts to necessarily provide a protection circuit and a dummy spare wiring merely for the purpose of protecting a spare wiring from the electrostatic charge. Furthermore, there is a critical limit in terms of countermeasure to cope with electrostatic charge without pursuing any further means so as to inhibit intrusion of an extremely large volume of static electricity. Further, provision of the protection circuit and the dummy spare wiring potentially hinders the down-sizing and cost reduction of the display device.